To achieve precision in a robot, it is important that the backlashes in the gear units of the wrist are as small as possible. For that reason, it is common to make the gear units adjustable. Several designs enabling adjustment of the backlash between two cylindrical gear wheels are known. However, many of these are space-demanding and, therefore, less suitable for use in robot wrists in which a slender design with good accessibility in narrow spaces, for example, inside car bodies, etc., is aimed at. Another frequently occurring disadvantage with prior art designs of this kind is that the after-adjustment thereof is a time-consuming operation.